In safety belt systems which have a belt tensioning device with a piston/cylinder unit, usually a flexible traction cable is used as traction transfer means between the piston of the tensioning device and the belt buckle. The flexible traction cable serves at the same time as an anchoring for the belt buckle and, in the buckled-up condition,, makes possible an alignment of the belt buckle for approximation to the belt webbing course. The smaller the resistance to bending of the traction cable, the better occurs the adaptation of the orientation of the belt buckle to the belt webbing course. However, on insertion of the insert tongue into the belt buckle, a too small bending resistance of the anchoring proves to be a disadvantage because the belt buckle can easily move laterally.